Device for forming a selvage

ABSTRACT

A device for forming a selvage with a fabric, comprising a rotatably mounted support for a binding thread supply and at least two binding thread guide members secured to an endless support means guided along an elongated endless path for guiding a corresponding number of binding threads from a binding thread supply to a fixed binding point, a common thread guide having a slot shaped guiding aperture being provided between the binding thread guide members on the one hand and the binding thread supply on the other hand, said guide being rotatably mounted in synchronism with the support means in its plane perpendicular to the plane of the support means, such that the distance between the support means and the adjacent end of the guiding aperture is minimum when the binding thread guide members are at or near the ends of their elongated path of movement.

United States Patent Van Mullekom I [54] DEVICE FOR FORMING A SELVAGE [72] Inventor: Hubert Peter Van, Mullekom,

Deurne, Netherlands [73] Assignee: N. V. Machinefabriek L. Te Strake,

Deurne, Netherlands [22] Filed: June 16, 1971 [21] Appl.No.: 153,607

[30] Foreign Application Priority Data June 19, 1970 Netherlands ..7009073 [52] US. Cl ..139/54 [51] Int. Cl ..'..D03e 11/00 [58] Field of Search ..l39/54, 48, 49, 5O

[56] References Cited UNITED STATES PATENTS 3/1955 Masson et al ..139/54 151 '3,698,441 1 Oct. 17,1972

1 Primary Examiner-Henry S. Jaudon Attorney-Marshall & Yeasting [57] ABSTRACT A device for forming a selvage with a fabric, comprising a rotatably mounted support for a binding thread supply and at least two binding thread guide members secured to an endless support means guided along an elongated endless path for guiding a corresponding number of binding threads from a binding thread supply to a fixed binding point, a common thread guide having a slot shaped guiding aperture being provided between the binding thread guide members on the one hand and the binding thread supply on the other hand, said guide being rotatably mounted in synchronism with the support means in its plane perpendicular to the plane of the support means, such that the distance between the support means and the adjacent end of the guiding aperture is minimum when the binding thread guide members are at or near the ends of their elongated path of movement.

2 Claims, 3 Drawing Figures The invention relates to a device for forming a selvage with a fabric comprising a rotatably mounted support'for a supply of binding thread and at least two members movable with a phase shift along an elongated endless path for guiding at least two binding threads In a well known device of this type, which is adapted to be mounted laterally of a weaving machine, the binding thread supply comprises two spools which are mounted diametrically with respect to each other in a rotatably mounted support. The spools are rotatably mounted in a cradle or cage which may rotate around a shaft perpendicular to the rotational axis of the spool and parallel to the rotational axis of the support, in a direction opposite to the direction of rotation of the support. A binding thread guiding member is provided on each of the cradles or cages outside the axis of rotafrom the binding thread supply to a fixed binding point.

tion of the associated spool. A planetary gear mechanism controls the rotational movements of the support and of the cradles or cages such that the binding thread guiding members, phase shifted through 180, describe a closed path of movement in the shape of a narrow loop, the plane of which is perpendicular to the beating up line for the reed of the weaving machine. The drive of the device is adapted to that of the shaft movements of the weaving machine in such a way that the binding thread guide eyelets are each at a longitudinal end of their loop shaped path of movement each time at the moment in which the weaving shed has been opened for insertion of a weft thread while after the weaving shed is closed they will move along the opposite legs of the loop towards each other, pass each other and again move towards the longitudinal ends of the loop shaped path of movement. Thereby both binding threads are twisted together and the projecting weft thread ends are closely interlocked between said binding threads.

The well known device is relatively complicated due to the special cradle construction for both binding thread spools and also due to the planetary gear system. Moreover, said complicated constructions transform the circular path of movement of the centers of the binding thread spools into the desired elongated path of movement for the binding thread guide members, but the aim in view, viz. keeping the length variations of the binding thread lengths between the binding thread guide members and the fixed point as small as possible and thereby keeping the tension variations in said binding thread lengths as small as possible, is not at all realized.

SUMMARY OF THE INVENTION The invention provides a device of the general type above referred to which is essentially simple in construction and in which is built an effective means for compensating the varying distance between the binding thread guide eyelets and the fixed binding point. 7

For this purpose the device according to the invention is characterized in that the binding thread guide members are fixed to an endless support means guided along the said elongated path of movement, a common thread guide having a slot shaped guide aperture being provided between the binding thread guide members on the one hand and the binding thread supply on the other hand, said guide being rotatably mounted in synchronism with said support means, in its plane perpendicular to the plane of the support means, such that the distancebetween the guide aperture and the supof movement.

The binding threads leaving the binding thread supplyare thereby guided together along the edge of the slot in the common rotating thread guide and are thereby more or less paid out or hauled in" through the slot shaped guide aperture in proportion to the increase or decrease of the angle between the binding thread lengths moving from the binding thread guide members to the fixed binding point. Experiments have shown that. through the thus realized more uniform pulling off and tension in the binding thread a more effectivesqueezing of the projecting weft thread ends is applied by the binding threads twisting together and thereby a selvage of better quality is obtained.

A further advantage of the construction according to the invention is to be seen in that it offers the possibility for the applicationof a common supply spool for the binding threads.

In a preferred'embodiment the common thread guide for the binding threads is mounted on the support for the binding thread supply whereby between said binding thread supply and the thread guide a thread eyelet positioned in the axis of rotation of the support is provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a perspective view of the device according to the invention and FIG. 2 and 3 show a perspective view and a fragmentary view looking in the direction of the arrow III in FIG. 2 respectively of the thread brake used in the device according to the invention and not further shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The device shown in the drawing comprises a support platform 1 adapted to be mounted laterally of a for instance pneumatic weaving machine, only a portion of the weaving shed formed by the lower and upper warp threads 2 and 3, and a portion of the reed 4 of the weaving machine having been shown in the drawing.

At the one end of the support platform 1 a foot piece 5 has been provided, a disc 6 mounted thereon being rotatable around its axis in the direction of the arrow. The rotatable disc 6 constitutes the support for a spool 7 rotatably supported by its shaft 10 between two supporting ears 9 projecting upwardly from the rotatable disc 6.

Two rods 11 projecting upwardly from the rotatable disc 6 support at their upper ends a thread guide 12, the slot shaped aperture 13 thereof being positioned diametrically over the disc 6. A transverse rod extending between the rods 11 comprises a thread guide eyelet 14- positioned in the axis of rotation of the rotatable disc 6.

The foot piece 5 comprises a square transmission not shown in the drawing between the shaft, likewise not shown, of the rotatable disc 6 and a connection shaft to a transmission drive 16 which is driven through a schematically shown chain transmission 17 by a shaft 18, the movement of which is derived in a manner not further shown from the main shaft of the weaving machine.

The transmission drive 16 is mounted against a frame plate 19 projecting upwardly from the support platform 1 and drives further a shaft 20 projecting from the side of the frame plate remote from the rotatable disc 6 and through a chain 21 drives a lower sprocket wheel 22 which together with an upper sprocket wheel 23 journaled in the frame plate 19 guides a chain 24 in a vertical loop shaped path.

The direction of movement of the chain 24 has been indicated with an arrow and the transmission ratios have been selected such that each revolution of the' chain 24 corresponds to a full revolution of the rotatable disc 6.

The chain 24 supports two thread guide eyelets 25 and 26 projecting perpendicularly from the plane of the chain and being mutually phase shifted through 180. The thread guide eyelets 25 and 26 serve for guiding two binding threads 27 and 28 to the fixed binding point in the reed beating up line 30. Both binding threads 27 and 28 are pulled from the spool 7 and thereafter move first together through the thread guide eyelet l4 and the thread guide 12 and thereafter each through the slot shaped passage 31 in the frame plate 19 to a thread guide eyelet 25 or 26 respectively.

The drawing shows the device according to the invention in a phase in which the thread guide eyelets 25 and 26 respectively are adjacent to the upper and lower points respectively of their path of movement determined by the chain 24, whereas the slot shaped aperture 13 of the thread guide 12 extends with its longitudinal axis substantially perpendicular to the plane of the chain 24. Said phase corresponds to that phase in the weaving cycle of the weaving machine in which the shed has been opened for the insertion of a weft thread 32 and for heating it up by the reed 4 into the cloth.

In the embodiment shown in the drawing the movement of the thread guide eyelets 25 and 26 is in synchronism with the shed changes effected by the healds of the weaving machine, which healds have not further been shown. As shown in FIG. 1 the binding threads 27 and 28 are thereby twisted together to they enclose and squeeze the ends of the weft threads 32 extending transversely thereto.

It will be clear that when the thread guide eyelets 25 and 26 as taken from the positions according to FIG. 1 move towards each other the length of the thread lengths between the eyelets 25 and 26 and the binding point 29 decreases up to the moment at which the binding threads 27 and 28 cross each other whereafter an increase of said lengths takes place. Said variations in lengths are now compensated by a simultaneous in crease and decrease respectively of the length of the thread lengths extending between the thread guide 12 and the thread eyelets 25 and 26. So in the phase shown in FIG. 1 the length of the binding thread lengths between the thread eyelets 25, 26 and the binding point 29 is about maximum while the length of the binding thread lengths between the thread eyelets 25, 26 and the thre d guide 12 is about minimum. Said compensating e ec is obtained by the slot shaped aperture'l3 in the thread guide 12 which in correspondence with the position of the binding threads pulled from the spool 7 closer to the slot ends pays off a greater binding thread length or when the threads are closer to the center of the slot hauls in more binding thread length respectively. Due to said compensating effect a uniform pulling of the binding thread from the spool 7 takes place. The required tension in the binding threads 27, 28 is guaranteed by the thread brake 33 shown in detail in FIG. 2 and 3. The thread brake 33 comprises a shackle 34 straddling radially the flange 7a of the spool 7, mounted at the end of an arm 35 which at its other end is mounted pivotally between supporting ears 36 on the rotatable disc 6. A sensing roll 37 has been mounted to one side of the shackle 34 which roll engages the binding thread packet of the spool 7 under the influence of a tension spring indicated at 38, tensioned between a point of the rotatable disc 6 and the arm 35. The flange 7a is clamped between the legs 34a, 34b of the shackle 34 with a force corresponding to the desired pulling off resistance, namely between a fixed friction pin 39 provided in the leg 34a and an adjustable friction pin 40 provided in the leg 34b (see FIG. 3). The adjustable pin 40 is urged by a spring 41, the tension of which may be adjusted by means of an adjusting screw 42. The advantage of said thread brake is that the relative velocity between the flange 7a and the friction pins 39, 40 is constant, namely substantially equal to the (substantially constant) pulling off velocity of the binding thread. i

I claim:

1. A device for forming a selvage with a fabric, comprising a rotatably mounted support for a binding thread supply and at least two members movable in phase shifted relationship along an elongated endless path for guiding at least two binding threads from the binding thread supply to a fixed binding point, characterized in that the binding thread guide members are secured to an endless support means guided along the said elongated path of movement, a common thread guide having a slot shaped guiding aperture being provided between the binding thread guide members on the one hand and the binding thread supply on the other hand, said common guide being rotatably mounted in synchronism with the support means in its plane perpendicular to the plane of the support means, such that the distance between the support means and the adjacent end of the guiding aperture is minimum when the binding thread guide members are substantially at the ends of their elongated path of movement.

2. A device according to claim 1, characterized in that the common thread guide for the binding threads is mounted to the support for the binding thread supply, a thread eyelet being provided between said binding thread supply and the thread guide in the axis of rotation of the support. 

1. A device for forming a selvage with a fabric, comprising a rotatably mounted support for a binding thread supply and at least two members movable in phase shifted relationship along an elongated endless path for guiding at least two binding threads from the binding thread supply to a fixed binding point, characterized in that the binding thread guide members are secured to an endless support means guided along the said elongated path of movement, a common thread guide having a slot shaped guiding aperture being provided between the binding thread guide members on the one hand and the binding thread supply on the other hand, said common guide being rotatably mounted in synchronism with the support means in its plane perpendicular to the plane of the support means, such that the distance between the support means and the adjacent end of the guiding aperture is minimum when the binding thread guide members are substantially at the ends of their elongated path of movement.
 2. A device according to claim 1, characterized in that the common thread guide for the binding threads is mounted to the support for the binding thread supply, a thread eyelet being provided between said binding thread supply and the thread guide in the axis of rotation of the support. 